title: Attosecond emission from chromium plasma.
abstract: We present the first measurement of the attosecond emission generated from underdense plasma produced on a solid target. We generate high-order harmonics of a femtosecond Ti:sapphire laser focused in a weakly ionized underdense chromium plasma. Using the "Reconstruction of Attosecond Beating by Interference of Two-photon Transitions" (RABITT) technique, we show that the 11th to the 19th harmonic orders form in the time domain an attosecond pulse train with each pulse having 300 as duration, which is only 1.05 times the theoretical Fourier transform limit. Measurements reveal a very low positive group delay dispersion of 4200 as2. Beside its fundamental interest, high-order harmonic generation in plasma plumes could thus provide an intense source of attosecond pulses for applications.
authors.affiliation: Institut national de la recherche scientifique–Centre Energie, Matériaux et Télécommunications, 1650 Lionel-Boulet, Varennes, Québec J3X 1S2, Canada.
authors.forename: L B
authors.initials: LB
authors.lastname: Elouga Bom
authors.forename: S
authors.initials: S
authors.lastname: Haessler
authors.forename: O
authors.initials: O
authors.lastname: Gobert
authors.forename: M
authors.initials: M
authors.lastname: Perdrix
authors.forename: F
authors.initials: F
authors.lastname: Lepetit
authors.forename: J-F
authors.initials: JF
authors.lastname: Hergott
authors.forename: B
authors.initials: B
authors.lastname: Carré
authors.forename: T
authors.initials: T
authors.lastname: Ozaki
authors.forename: P
authors.initials: P
authors.lastname: Salières